Recently, aortic valve replacement procedures using a catheter (TAVI (trans-catheter aortic valve implantation) or TAVR (trans-catheter aortic valve replacement)) have been attracting attention. The aortic valve replacement procedure is carried out, for example, in a procedure room equipped with an X-ray diagnostic apparatus. That is, the aortic valve replacement procedure is a technique for placing an artificial valve in a heart of an object while observing fluoroscopic images collected by the X-ray diagnostic apparatus in real time.
With the aortic valve replacement procedure, it is important to place the artificial valve at a precise location by referring to fluoroscopic images. Specifically, an aim is to place the artificial valve such that a lower end of the artificial valve will be below a bottom of a natural valve and that an upper end of the artificial valve will be above a tip of the natural valve leaflet and below a coronary arteries.
A technique has been disclosed which displays a fused image based on an angiographic image and fluoroscopic image of the object.
In the aortic valve replacement procedure, if there is a calcified area on a coronary artery wall, when the catheter is advanced, a tip of the catheter may sometimes come into contact with the calcified area. When placed in contact with a distal end of the catheter, the calcified area can separate from the coronary artery wall and flow through the coronary arteries, causing cerebral infarction as a complication.
To prevent the distal end of the catheter from coming into contact with calcified areas, it is necessary to present appropriate real-time images to a surgeon, and a conventional technique displays images obtained by fusing an entire angiographic image with real-time fluoroscopic images using a bone or the like as a landmark. With such a conventional fused image since there is a deviation between the fluoroscopic image and angiographic image in coronary artery location which moves along with heartbeats, it is very difficult to prevent the distal end of the catheter from coming into contact with calcified areas by watching the fused image.